Ra, god of the afternoon sun
Few deities have attained as a high a position with the mortals as Ra, and his ego matches his worship. Confident, elitist, and with a nasty temper, you can tell that all those violent eye-goddesses are definitely Ra’s daughters. The rage and power of the sun is known to all, and his grip on control of Kemet ever since the 3rd Dynasty can be tyrannical to some, but Ra has been difficult to shake from his position. Well, until Amun came along, anyway.
Ra understands the value of both power and politics. As a result he has a habit of marrying his daughters (of which most of his children are daughters, given he has only two sons) to deities he wants to control or keep subjugated under his thumb. And that worked great up until he married Mut to Montu, to gain some control down in the area of Waset… until Mut decided she’d rather date that hot Nubian god named Amun, and Ra’s problems formally began.
He hates, hates, hates Amun. There is nothing Ra despises more than the fact that Amun gets the honorific position in their Amun-Ra synchronism. Kingship has always belonged to Ra and his carefully decided descendants, and when the Third Intermediate Period came along and the Priests of Amun decided they ought to be running the south instead of the pharaoh in the north, or that set of Nubian pharaohs empowered by Amun, well… suffice to say Ra is on the verge of an all-out war with Amun, a war that no one can afford to engage in with all the changes happening in the world around them. Who’s going to defend Kemet against the Assyrians if Ra and Amun are busy in-fighting?
Some bonus information about him:
In search of power and immortality like the Sumerian gods, who did not have to deal with ba’s and ka’s, Ra was cursed early in his life to reflect his three names - Khepri, Ra, and Atum (though these are technically the nicknames for each phase of his identity and not the names themselves). In simplified form: as the sun changes positions in the sky, he experiences a mortal life and is reborn at sunrise as Khepri, becomes strong and youthful again as Ra at high noon, then ages into an elderly form as Atum in the evening before becoming reborn again.
He was cursed by the snake god Rerek right before the First Intermediate Period, in which Ra started physically changing as he entered each phase. The story is a whole thing on its own that stretches back to Ra’s jealousy over Rerek’s ability to revive his form directly as an ahk-spirit (or divine soul) without having to unite a ba and ka together. Ra could see that Rerek’s divinity was different and was immensely jealous over it. (Bonus lore: Rerek is the snake that stole the herb of immortality from Gilgameš. You pull that kind of shit and you get kicked out of your homeland by Ninazu.)
Ra’s aging isn’t exactly like a mortal’s in its transition. At 6 AM, the sun rises and he is Khepri, who appears about 15 years old. He slowly ages at a rate of 2.5 years/hour until 12 PM, when he looks about 30 and becomes Ra. He ages at a rate of 2.5 years/hour again until he’s 45 at 6 PM, then continues aging at that same rate. At midnight, when he appears about 60, his rejuvenation triggers and he starts aging backwards at a rate of 7.5 years/hour then eventually reaches the age of Khepri at 6 AM and starts aging forward again at the slower rate.
This means that when Ra encounters Apep in the seventh hour of the night (1 AM) his rejuvenation has already triggered and he’s one hour into reversing his aging back into Ra (which takes, in this compressed time period, three hours). So he’s 52.5 years old, roughly, when he fights Apep as Atum. Because he’s not at his strongest (30-45) he struggles with fighting the serpent alone and needs assistance of other gods—though Atum is still very strong, and by no means helpless.
Ra does have three names. Names are powerful and allow a degree of compelling against the being they’re tied to, so deities keep their true names secret. Aset knows Ra’s true name, but she doesn’t know Atum or Khepri’s. This means that from 3 AM - 6 AM and 12 PM - 6 PM, Aset can compel Ra using his true name.